Blogroll

Archive for the ‘Science’ Category

The National Aeronautic and Space Administration (NASA) and the German Aerospace Center (DLR) are to continue their collaboration on the Gravity Recovery and Climate Experiment (GRACE) mission on till 2015. Full story here

Image courtesy Trent Schindler and Matt Rodell, NASA

Results from this mission have proven invaluable in tracking the amount of underground water, ice, and global sea levels. This is of key essence in preparing for hazards related to water shortages, rising sea levels, and ocean currents. It is also important that scienctists and researchers on the African continent take advantage of such data to develop intelligent systems that would help guide the development of climate adaptation, disaster preparedness, and mitigation efforts. The role of international cooperation, capacity building, and financial support is very crucial here. Efforts should also be made to engage communities proactively, and empower them to cope with these foreseeable challenges.

Satellite images captured the flow of dust storms that were responsible for hazy conditions across parts of West and Central Africa in Mid March 2010. The image shown below shows the dust storms as they spread from the Red Sea right across the continent, and extend till the Atlantic Ocean.

Dust storm across Africa (Source: NASA Earth Observatory)

News reports across Nigeria, where there were hazy conditions in many parts of the country, attributed the dust storms to climate change. Other countries affected include Cameroon, Chad and Niger. African countries need to invest in advanced meteorological practices to better prepare and inform their citizenry, and to avoid panic and undue speculation when untoward weather events arise. Misinformation can take a toll on the economic livelihood of the nation.

Development of space capabilities and the use of space imagery and its derived value-added products can help enhance the knowledge-based economy that many African nations currently strive for. Indeed the rise of technological advantage as an integral part of economic intelligence lays the responsibility of integrating technology-based knowledge and forecasting into the practice of aspects of human endeavour like health, agriculture, transport, governance etc.

Africa is blessed with a rich social, moral and cultural heritage, there is no doubt about that. The land is also rich in bountiful stores of natural resources. It’s people however are its greatest assets and these have made their mark not only on the continent but indeed all over the globe and even in space exploration. That is Africa.

Of particular significance though, is the uniqueness and beauty of Africa’s geophysical structure. It’s breathtaking landscapes, lush greenery, magnificent forests, cascading waterfalls, gorgeous hills and mountains, “proud ancestral savannas”, and seering yet awestriking deserts, are some of the features that have made Africa the prime allure of explorers, the daring and adventurous for centuries.

The Group on Earth Observation (GEO) lists ecosystems and biodiversity as two of its themes and societal benefit areas. Space technologies can play a major role in supporting efforts at conserving the state of our environment. These efforts thus need to be augmented through the use of earth observation and other space capabilities in environmental monitoring and conservation. There is an increasing role to be played by the integration of technologies in development aims because they offer boundless opportunities to optimize resources and increase efficiency.

The ‘African Heritage from Space Series’ is being launched to connect these potentials of space technology to the God-given magnificence of Africa’s ecosystems and entire landscape. This will showcase the varied scenes of beauty that exist in different parts of the continent as seen through the eyes of space-borne instruments. Furthermore, like apples of gold in settings of silver, each image would be set within the context of what is and what could be.

The first image in this series is of the Namibian Desert and it was taken by an astronaut on Expedition 22 on the International Space Station (ISS). It is made available through the NASA Earth Observatory.

Tsauchab River and Sossus Vlei Lakebed, Namibia (NASA)

The Namibian desert extends for about 81,000 sq. km. and it is from this Namib (Nama for vast) desert that the country of Namibia gets its name. The driest desert in Africa and the oldest in the world, this richest of sources for diamonds captivates endlessly with its awestriking dunes that remind one of the Martian landscape. It has a unique blend of animal and plant varieties that make up its ecosystem. One of the most popular of these is the Welwitschia mirabilis with its single pair of leaves, existing in an order of its own. See a video of the desert and its enchanting features below.

The desert has long inspired paintings, photographs, poems, historical writings and other works of art. It has also had its fair share of scientific study. The sand dunes pictured in this image are the tallest in the world, reaching up to a height of 300 metres above river bottom. The desert however is one of the world’s driest and the future of its species, though rugged, is a concern for conservationists and environmental biologists. It is also a location for mining ventures which together with farming, if not carefully monitored, could further pose a challenge to its ecostability. It is a coastal desert that is gradually encroaching westward to reclaim land from the ocean.

In the quest for renewable energy solutions that could serve to meet the world’s energy needs in a cost-effective way, there are many options that are being proposed. Some of these options are quite interesting, a number are ingenious and laughable, and yet some border on the fringe of the bizarre, and on being outright outrageous.

One particular example of alternative energy solutions that holds huge potential for the many parts of Africa with many sunny days in a year is the PS 10 in Sanlucar le Mayor, 25km west of Seville, Spain. It is the world’s first commercial tower technology solar thermoelectric power plant. See the video below.

The search for appropriate locations to derive maiximum yield from solar energy has led some to consider the possibility of moving beyond the earth’s surface, above it’s immdiate atmosphere, and into the vastness of space to tap this abundant resource. The case for Space-Based Solar Power(SPSP) or Space Solar Power (SSP), as it is called, is made by those who seek to overcome the huge loss of solar energy that occurs as radiation from the sun loses it’s value as it passes through the earth’s atmosphere to reach its surface where most solar panels exist. Moreso, unlike solar panels on earth which are subject to meteorological and day/night changes, a satellite in space bearing a solar panel can have uninterrupted reception of solar energy for conversion to electricity and onward transmission to the Earth’s surface. This idea has been a subject of intensive research by a number of developed nations who predict drastic energy shortages and seek to augment current energy supply means with power gathered from space. This energy can then be beamed back to earth solving the power generation and transmission questions by systematically splitting transmission into sending (from space) and receiving (on ground) components. They can then use existing distribution networks.

Does this approach hold any special benefit for Africa? Are there equally efficient options on the continent? Are current and potential energy shortages faced by the continent due to a dearth of energy sources or lack of utilization of existing energy sources? Does Africa have the potential of supplying power to other continents? Whose responsibility is it to make Africa energy self-sufficient and even commercially capable in supplying other states?

If in spite of the abundance of solar energy sources in Africa, people prefer to invest in going all the way to space, a technology solution that is probably 5 decades away from being deployable on a commercially feasible scale, then that should point to the fact that Africa in many ways has the primary responsibility to invest in and develop its own viable energy sources. This may be their solution to generating in Africa and transmitting to Europe, Asia or America. The problem with this option is that the risk of failure is high compared to the incurred investment especially since the technologies have been untested on the scale that it would take to make economic sense. However their efforts in conceptualising and developing new technologies to adapt to future change is commendable, and that should be emulated across Africa. Africa needs a breed of forward-looking engineers, entrepreneurs and social policy makers to help it cope with the needs of the present and the challenges of its future. The lesson there is probably not that some are willing to try something crazy rather than come to invest in Africa, but that we had better get the message that the rest of the world will not wait for Africa to solve its own problems.

The provision of alternative energy sources to drive the machines of development in Africa, and indeed globally, is a major issue. This is further heightened by the scientific and economic possibilities that surround the commercial deployment of new technologies that use renewable energy sources as alternatives to coal and petroleum. Governments, research institutions, and private entities alike have all embarked on quests to discover, develop, and deploy efficient and renewable energy solutions.

Darling Wind Farm, South Africa. (Source: BBC News Africa)

The growth of carbon-efficient technologies has helped to fuse considerations such as cost-effectiveness and environmental impact into the primary concern of technical feasibility. Some of the options being explored include wind, hydroelectric energy, biomass, and solar energy.

In spite of its having a rich abundance of each of these energy sources, Africa still reels under the lack of energy to drive development and economic growth. This is largely because technological and organisational know-how is needed to exploit these options and most parts of the continent still fall behind in this aspect.

Africa stands at a particular advantage with respect to solar energy. The development and commercial exploitation of this resource should have long been a priority of many African governments. The space programme has long relied on solar energy to drive its exploratory missions.

SMART-1, ESA’s technology demonstration satellite to the moon, used highly efficient solar power solutions to accomplish new technological feats. See a video of SMART-1.

There are many lessons to be learned here by countries seeking to profit from the utilisation of solar energy. The hardening of spacecraft components to help them cope with the harsh extremes of the space environment can be adapted to improve the effiency of solar energy hardware deployed in desert-like conditions. Deserts are notorious for their very hot days and extremely cold nights. Hardening helps technologies deployed in harsh environments to stay efficient and deliver for much longer. If man can successfully deploy structures like the International Space Station’s solar array wings to provide consistent power supply for man’s presence in space, then nothing stops Africans from repeating something that does not come near that as a technological feat.

International Space Station showing solar arrays (Source: NASA)

Profitable exploitation of solar power is possible and needed in Africa. The technologies are available, what is needed is the political will and economic sense to drive its successful implementation. Some people are already making efforts in this direction.

A graduate of the International Space University, Ayodele Faiyetole, believes in the potential and impact of solar power. He is overcoming the resistance of his environment to deliver voltage and light to communities hitherto enshrouded in darkness and ignorance of the possibilities that the sunlight around them can bring. He recently received the Todd B. Hawley Space Visionary Award for his achievements. Read more about him here

Solar panels and solar energy options have advanced in the last few decades and the field is still growing. This is a key area where Africa can make its mark and pull its people out of darkness to light.

The African Resource Management Constellation (ARMC), a collaboration currently involving Nigeria, South Africa Kenya, and Algeria. Initially conceived around 2004, when it was named the African Resource and Environmental Management Satellite Constellation, the initiative was meant to develop a constellation of satellites to provide real time, unrestricted and affordable access to satellite data to support effective environmental and resource management in Africa. Three meetings held in May 2005 in Algeria, September 2005 in Stellenbosch, RSA, and November 2005 in Abuja, Nigeria, demonstrated the commitment and momentum at the early stages of the project. During this period, a steering committee was formed and a plan of action developed to move the process forward. Other workshops held in Algeria in 2006, Pretoria, RSA in 2007 and in Kenya in 2008. These with the international awareness generated by the initiative, all helped to lay a good foundation for its success. The space agreement on the African Resources Management Satellite Constellation (ARMC), which is a Memorandum of Understanding between the partners, was signed by the governments of the four countries on the 7th of December 2009 during the Third African Leadership Conference on Space Science and Technology for Sustainable Development that held in Algiers, Algeria.

As proposed, the constellation would help provide easy access to satellite data for end users in the following fields: disaster management, food security, public health, infrastructure, land use, and water resource management. It would thus support activities such as urban development, land use monitoring, and mapping for the surveillance of climate change effects. A constellation design was adopted that would have each satellite equipped with a 2.5m resolution panchromatic imager and a 5m resolution multispectral imager in 6 multispectral bands. Data from these identical satellites would be gotten through an integrated ground station. From the ground station, efforts would be made to ensure that the satellite data reach the end users all over the continent, as close to real time as possible.The program would also include capacity building initiatives and the development of low-cost multi-source ground receiving stations to aid the less privileged countries who can gain access through these stations to remote sensing and meteorological satellite data.

Algeria launched its first satellite, Alsat 1 in 2002 as part of the UK-led Disaster Management Constellation (DMC) programme. Nigeria launched its own first satellite in 2003 under the DMC programme. Both satellites were constructed by the Surrey Satellite Technology Limited, Guildford, United Kingdom. Nigeria, with Chinese support, also launched, the now failed, Nigcomsat-1 in May 2007. South Africa launched Africa’s first satellite (SunSat 1) built by the University of Stellenbosch, in February 1999. This last September it launched its second satellite, the Sumbandila Sat, aboard a Russian rocket. Although, Kenya inherited offshore launch facilities (San Marco launch platform) from the Italian space programme, it has no satellite of its own.

There are certain infectious diseases that are said to be climate sensitive. These diseases are described thus because of the observed change in their epidemiology following the probable effects of anthropogenic global warming.

Source: National Science Foundation, USA.

Some of these diseases represent the common face of the human-vector interaction as mediated by man’s environment. They also represent a huge health and economic burden to affected populations. It is thus important, in instituting control measures to combat the spread of these diseases, that there be a functional understanding of the various environmental parameters that influence the biology of these vectors and the natural history of the diseases that they transmit. Other non vector-related occurences such as heat waves, with attendant adverse health effects, also need to be studied and predicted.

The role of space technologies is very important in monitoring and understanding the influence of environmental parameters on vector biology and disease transmission cycles. Typically, earth observation systems that routinely monitor the environment give very useful data that can be adapted for the study of vectors, their associated diseases and other climate sensitive diseases. These systems operate with sensors located in water bodies, on the earth’s surface, above the earth’s surface, in the atmosphere and in outer space. These all combine to give a continuous stream of data to inform the scientific study of the climate and how its patterns are influencing the spread of diseases. This studies involve the complex task of disease modeling to aid public health interventions in curbing the spread and effect of such diseases. Interventions include chemical, physical, biological and pharmacological measures such as vaccinations, the distribution of Insecticide Treated Nets (ITNs), use of repellants, drainage of stagnant water, etc.

The advantages of space-based imagery for these studies include its reliable supply of data on a range of environmental parameters such as precipitation, temperature, Vegetation Indices, topography, etc. It makes these data available at varying temporal, spatial and spectral resolutions. Satellite data can be acquired at reasonable costs and much of what is freely available is being put to good scientific use already. To improve access to this, it is important that African countries invest in developing technical and scientific capacity to put them at the helm of disease studies affecting their environment and populations.

The dangers that petroleum oil spills pose to the environment and the health of marine life and humans has been well documented. This short post, a follow-up to the last one, shows how optical satellites can be used in monitoring the state of the environment and specifically, in this case, following an offshore oil spill. The images published by the NASA Earth Observatory showing the use of optical remote sensing satellites in the detection of oil spills in the Timor sea are a good example of how these earth observing satellites can be put to good use for this purpose. The images are available here and here. The use of radar remote sensing for the same purpose, as briefly mentioned in the last post, can be further seen in these images from RADARSAT and TERRASAR X

Oil Trading Nations (Source: Wikipedia)

The number of African countries with investments in the petroleum sector is growing. Nigeria, Algeria, Libya and Angola are major oil producers while 18 African countries in all are in the oil producing league of nations. What does this imply? The responsible use and control of a nation’s resources lies in the hands of its government and people. Satellite monitoring of petroleum resources is thus an important part of the ‘toolbox’ for effective monitoring by countries that produce or even trade in oil. Most oil spills occur at the point of loading or off-loading of oil at ports and other transfer points (See the example of the Bonga deepwater oil spill below). This requires a system of laws and other regulatory mechanisms with sufficient power to monitor the uses and misuses of petroleum that could have a negative effect on the environment and human life. Technologies such as satellite imagery/remote sensing, geo-positioning equipments, Geographic Information Systems (GIS) and other applications have a crucial role to play in supporting these aims.

Bonga deepwater oil spill December 2011
Article by Brandon Kim on the oil spill from the Bonga deepwater facility on December 20 2011 off the coast of Nigeria.

The plight of African farming and the need to develop adaptive systems to cope with the changes that may be forced on African populations due to environmental change has been touched on in an earlier post. The role that early warning systems can play in shaping this adaptive response has also been discussed in another post. This post has as its focus an examination of the interactions, as often abound in nature, between factors in the African environment, and how these interactions could contribute to the challenges being faced with precipitation, drought and food security. The role of space science and technology in arming researchers, scientists and government policy makers with the right information and predictive tools to evolve appropriate and evidence-based responses to these challenges is highlighted.

The flow of dust on the African continent is abundant. It has some of the world’s largest sandy deserts- the Sahara (the world’s largest hot desert), the Kalahari and the Namib. The Arabian desert extending from Egypt to Iran is also close by. These supply a stream of dust propelled by the trade winds and which blow huge amounts of dust over the continent towards the equator and the oceans. The effect of these dusty winds on rainfall is by acting as aerosols and interfering with the coalescing of water droplets in rain clouds. This leads to a dispersion effect on the water droplets, preventing rain drop formation and hence precipitation. The scourge of reducing annual rainfall on many parts of the African continent is as shown in the picture below. The socio-economic impact of this is better avoided. Food and water shortages in Kenya this year left about a third of the population in need of aid.

Another effect of dust clouds is on Sea Surface Temperature (SST) and its ensuing effect on tropical storms. Although not a major problem for the continent on its Atlantic end, the propagation of El Niño-La Niña events has been linked to droughts, tropical rainfall, storms, floods, malaria and even cholera incidence in some parts of Africa. The El Niño Southern Oscillation (ENSO) also bears links to other diseases. Space technologies play a crucial part in defining and predicting the occurence of these events and may also aid the mitigation process.

Amongst other uses of space technologies in keeping track of these environmental variables, their use in monitoring groundwater has also been demonstrated. Using results from the Gravity Recovery and Climate Experiment (GRACE) a joint NASA and DLR mission, a team of NASA researchers demonstrated receeding groundwater stores in India, most likely due to irrigation that has relied on these groundwater sources. Thus using satellite technology it is now possible to generate a comprehensive monitoring system that keeps track of not only the environmental variables affecting precipitation and drought, but also the effectiveness and effect of countermeasures developed as part of the anti-drought response.

Images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the NASA Terra and Aqua satellites have been very useful in tracking the spread of dust on and away from the African continent. This has also helped in guiding researchers and scientists in observing the links between this spreading dust and various climatic and biological phenomena.

The image above depicts the flow of dust off the west coast of Africa. The following description from the NASA Earth Observatory states that,

“The Sahara experiences extreme variations in land surface temperature—from freezing temperatures at night to more than 54.4°C (130°F) during the day. The extreme daytime heating in the Sahara Desert, especially during the summer, causes instability in the lowest level of the atmosphere. Dust-laden air rises and begins moving westward. As the air travels—a trip that often takes several days—it continues heating. When this Saharan Air Layer moves off the African coast and over the Atlantic Ocean, it is undercut by a cooler, wetter layer of air. Air normally cools with altitude, but the Saharan Air Layer passing over cooler air currents causes a temperature inversion, which suppresses mixing. As a result, Saharan dust often travels across the Atlantic, sometimes remaining visible throughout the trip.”

Dust moves freely across the continent and blows off the coast driven by the various winds and thus goes to contribute to the soil profile of other parts of the world. It also settles in the ocean along its way adding nutrients and thus embellishing oceanic ecological patterns.

But what effect does this have on human health and livelihood? In looking at that we would like to consider the amount of the earth’s surface that is potentially exposed to airborne dust. Airborne dust has been described, by the National Institute of Health (NIH) in the United States, as the primary source of allergic stress worldwide. Deserts (in this case referring to non-polar arid zones) are major sources of dust particles.

D. W. Griffin has worked on using satellites to monitor the global spread of dust and linking this with its effects on ecology and human health. His work (in this paper with C. A. Kellogg) identified these effects on life forms, both human and in the oceans, and on various continents. The identified effects include coral bleaching, algal blooms and allergenic effects on humans, including aggravating asthma. This may not be solely due to desert dust but the increased concentration of these dust particles, some as fine as 2.5 microns, in combination with other industrial and environmental pollutants may play a role in immunogenic responses that cause ill health. The human respiratory mucosa usually traps dust particles and tries to clear the respiratory passageways of these irritants. However, these very fine particles may exacerbate that response. This is of more serious concern in individuals with compromised respiratory and immunologic responses.

A lot of the research in this area has focused on the Trans-Atlantic effects of dust spread. This has had effects in the USA and the Carribeans. Griffin reported studies stating a 17 fold increase in paediatric asthma between 1976 and 1999. Other studies identified a relationship between dust events and hospital asthma visits. This however was not solely due to dust of African origin, which was said to have contributed (~50%) alongside other sources of dust activity. Also, the link between dust events and the epidemic prone disease, meninigitis, is already being investigated.

In strengthening the capacity to detect which dust events and sources are responsible for some disease events in Africa, the use of satellite technologies play a very important role. This occupies a relevant area of research alongside other initiatives to boost the monitoring and reporting capacity for Air Quality Indices. There are various aspects of using available resources for strengthening our awareness of the effects of inspired air on human health. The training of scientists and continued collaboration with the environmental sector, meteorologists, climatologists, public health researchers, and healthcare policy makers is a definite step towards developing a functional warning system with strong interventional capability. Academic research institutions can mobilize resources to develop training programmes in support of this crucial area of need. Ultimately such efforts may not go far without governmental support. The role of environmental and healthcare organizations in developing awareness and response capacity and acting to engage political leadership is also of importance. Hand in hand, individuals and associations can work to bring about a safer and securer environment to live and work in.

You can follow the progression of the Saharan Air Layer (SAL) on this site with frequently uploaded satellite images.